Thursday, December 17, 2009

Attention Fellow Chiropractors - It's time to forget the "old school", read this and finally understand Why What You Do Works...

This is reprinted from Dynamic Chiropractic Magazine and once you understand it, proves to be a really powerful article and should provoke the desire to learn more. Many of our chiropractic brethren continue to cling to the old chiropractic vitalistic theories and fail to keep their eyes open for the actual physiology behind how and why chiropractic works. There's no question that chiropractic works....and it works beutifully at that, BUT the question is why does it work?

Read this article by one of the great minds of our profession and you'll begin to understand.

Subluxation and the Nervous SystemBy David Seaman, DC, MS, DABCN

Subluxation remains a topic of heated contention, as does its relationship to the nervous system. Some still view the subluxation as a "bone out of place" that is returned to its proper position with an adjustment. That this view persists is somewhat surprising when we consider that back in 1967, Len Faye first introduced the dynamic subluxation complex to his students at the Anglo-European College of Chiropractic, in Bournemouth, England, and then to us here in the United States in the late 1970s and early 1980s. Faye described the subluxation complex as a joint that hypomobility, myopathological changes in spinal musculature, histopathology of spinal structures, inflammation, and related neurological dysfunction termed "neuropathophysiology."

Joint Complex Innervation
To understand the neuropathophysiology of subluxation, we need to be aware of the innervation of the spinal joint complex. Nociceptors and mechanoreceptors are the primary sensory receptors that innervate joint structures, including synovia, joint capsules, bone, ligaments, tendons, muscles, and blood vessels. The predominant receptor is the nociceptor. More than 90 percent of joint innervation is nociceptive, originally determined by animal studies,1 then confirmed in studies with human spinal joint capsules. (2) In short, there is a paucity of mechanoreceptor innervation of the joint capsule, and an abundance of nociceptive innervation, which should seemingly lead our profession to dig deeply into the nature of nociception. There seems to be less nociceptive innervation of muscles; we have about an equal balance of nociceptive and mechanoreceptive receptors, (3) which means that nociceptive innervation of muscles is still significant.

Clearly, the afferent innervation of the spinal joint complex favors nociceptive receptors. At this point, readers should appreciate that nociceptors are not pain receptors and that nociception does not equate with pain. This misinterpretation is common throughout the extent of health care professions, as texts such as Guyton's Physiology use "pain receptor" and "nociceptor" interchangeably.

Different nerve fiber types are associated with nociceptors and mechanoreceptors, and nerve fibers are classified in two fashions. There is an alphabetical classification, which includes A, B, and C fibers that correspond to both afferent and efferent fibers. There is also a Roman numeral classification system, reserved exclusively for afferent fibers, designated as group I, II, III, and IV fibers, afferents, or units. These classification systems tend to make comprehending the nature of nerve fibers more difficult than it should be.

The best way to view this is from the perspective of fiber size. Generally speaking, there are A-alpha, A-beta, A-gamma, A-delta, B and C fibers, differentiated by their size, with A-alpha the largest and the C fibers being the smallest. Depending on their place of origin, A, B and C fibers can be afferent or efferent. Nociceptive afferents, for example, are either A-delta or C fibers; when these fibers leave peripheral tissues with which to travel to the spinal cord, we know that they are nociceptive. So far, so good, right?

The confusion often begins when the overlap between the alphabetical and numerical system is presented. All we need to know at this point is that A-delta afferents equate to group III units, and C fibers equate to group IV units. Practically speaking, this means that joints are predominately innervated by A-delta/group I fibers and C/group IV fibers. Actually, C-fibers/group IV units are the predominant afferent fibers that leave joints.
When we consider joint innervation for the purpose of understanding the neurology of subluxation, we need to know that C-fibers or group IV afferents are the primary nerve fibers that innervate spinal joints. Stated again, joints are innervated predominantly by C-fibers/group IV afferents.

Compared with nociceptors, significantly fewer mechanoreceptive afferents leave our joints. A-alpha fibers equate with Group Ia and Ib afferents, while A-beta fibers equate to group II units. Significantly more group I and group II units innervate muscle compared to joints.
This heavy concentration of nociceptive fibers in joints suggests that we are basically built to experience joint pain, which bears itself clinically when we consider that most people experience back or neck pain during their lives. Whenever asked why back pain is so common, we should state the simple truth: our spinal joints are densely populated with nerve receptors that sense tissue injury and inflammation, i.e., nociceptors.

Subluxation Neurology
The above description of fiber types can be found in most anatomy, neurology and physiology texts. What we don't read in such texts is that spinal dysfunction/subluxation will influence the activity of the various fiber types. Nociceptors are activated by tissue injury and the chemical mediators that cause inflammation, while mechanoreceptors are stimulated by normal movements. Accordingly, spinal injury is likely to increase the firing of nociceptors however, the activity of mechanoreceptors is likely to be reduced because with injury, inflammation, nociception and pain, there will be less movement afforded to the injured joint and therefore, less mechanoreceptor activation. The outcome of this pattern of receptor activity associated with the subluxation complex will be discussed in future columns. Suffice it to say that increased nociception and reduced mechanoreception can cause pain, visceral symptoms, problems with motor control and proprioception, or no symptoms at all. (4) The important point to appreciate now is that the subluxation complex will alter the firing of spinal tissue nociceptors and mechanoreceptors, and this will lead to various symptoms that we often encounter in the clinical setting that respond to chiropractic care. So, when we think about subluxation, the subluxation complex, or joint dysfunction, we need to think about receptors and afferent fibers.

Although the spinal nerve travels through the intervertebral foramen, it is rare for a bone-on-nerve subluxation to occur. There has to be significant facet hypertrophy or disc collapse, not a common encounter in clinical practice; perhaps 1 percent of the population with back pain suffer with this problem.(5) When such neurocompression does exist, surgery and/or heavy medication is often the choice of care.

What makes the bone-on-nerve subluxation popular is that we can visualize the spinal nerve in books and cadaver specimens; however, we cannot see nociceptors or mechanoreceptors. For us humans, it is far easier to believe something that we see, compared with something that is invisible to the naked eye. Despite this tendency, we must understand that spinal joints and muscles have a massive nociceptive and mechanoreceptive innervation pattern that is profoundly influenced by the subluxation complex. While not visible, they are the reason patients come to our offices.

About Me

Dr. Todd
M. Narson graduated from Logan College of Chiropractic in 1990 and is a Diplomate
of the American Chiropractic Board of Sports Physicians (DACBSP). One
of only 240 DACBSPs in the country; 1 of 10 in Florida and the only one
practicing in Miami-Dade County, FL. . In 2011 Dr Narson was granted
anInternational Chiropractic Sports
Science Diploma (ICSSD)by
the International Federation of Sports Chiropractic (F.I.C.S.) and is the only
chiropractor in South Florida with such international credential.Dr.
Narson was a member of the COPAG international sports medicine team at the XVI
Pan American Games in Guadalajara, Mexico, October 2011.During his tenure at the Pan
American Games, he worked with teams from all over the Western hemisphere
including Chile, Cuba, Ecuador, Colombia, Dominican Republic, Argentina, Peru
& Mexico.

Dr.
Narson has lived in South Florida for over 30 years. He is a 2-term
past president of the Florida Chiropractic Association’s Council on Sports
Injuries, Physical Fitness & Rehabilitation and has been on their governing
board for 8+ years. He was honored as the recipient of the coveted Chiropractic
Sports Physician of the Year award in 1999-2000.

Dr.
Narson was also a credentialed treating physician in the Poly-Clinics at the20th
Central American & All Caribbean Sport Games (XX Juegos Deportivos
CentroAmricanos Y Del Caribe), Cartegena, Colombia.

Dr.
Narson in inventor and developer of the Narson Body Mechanic N6, a soft tissue
"multi-tool" used for Instrument Assisted Soft Tissue Mobilizations
techniques such as FAKTR and others. He has been an M1 & M2 certified
Graston Technique(r) provider for the past 10 years and is trained in FAKTR
advanced soft tissue mobilization & rehabilitation techniques.

Along with Allen Miller, Dr. Narson has co-authored the paper: Protocols
For Proprioceptive Active Re-Training Boards (balance boards).
Published in Chiropractic Sports Medicine Magazine; the Journal of the American
Chiropractic Board of Sports Physicians, Vol 9, No. 2, May 1995 pp 52-55.

Having
chiropractors associated with hospitals was unheard of here in Florida until
1994 when a small group of chiropractors were credentialed here in South
Florida. As some of the first chiropractors in the country to have such
privileges, Dr. Narson was part of the original group accepted into the
Chiropractic Division at Golden Glades Regional Medical Center.

Coining
the term: “Natural Sports Medicine” Dr. Narson has been
educating personal trainers at local gyms and health clubs for several years in
including well known clubs such as Club Body Tech, Crunch & David
Barton’s (Original) Gym in South Beach.

He was medical director
for the 1998 Pan American Race Walk Cup held in Downtown Miami
&

He also served as Medical
team member and treating physician for the 1999 Pan American Tae Kwon Do
Regional qualification Tournament for the Sydney 2000 Olympic Games

Meet Director/treating
physician for the Sydney 2000 Para-Olympic Qualifier/USA Open-Power
lifting held in North Miami.

In
1994 Dr. Narson was asked to join the professional boxing team of Don
King’s light weight contender: Lamar “COSHISE” Murphy and was named
“Team Physician”. Providing the fighter with performance enhancement training
techniques, nutrition and chiropractic care, Dr. Narson worked with the boxing
trainers and traveled with team COCHISE Murphy around the country during his
1995 quest for the WBC lightweight title.

Coors
Lite, Gatorade, Jose’ Cuervo and Jiffy Lube were a few
of the sponsors of large sporting events such as beach volleyball, triathlons
and professional NASCAR racing that have credentialed Dr.
Narson as an on-site treating physician. Dr. Narson has also been
included on the sports medicine teams at the Miami Grand Prix, the Florida
Sunshine State Games as well as other national and international
sports competitions.

Dr.
Narson has had the privilege of being invited to treat the cast and crews of
the Broadway Shows: Les Miserables, The Rockettes, & Damn Yankees. To
date, Dr. Narson has spent over 1000 hours working “on field” with athletes at
various sporting events from local regional athletes, to world class Olympians
& professionals.

Sports
medicine is on the cutting edge of healthcare, Dr. Narson uses his experience
and education with athletes and sports injuries to treat all patients, not just
athletes. Dr. Narson feels everyone deserves the knowledge of a
sports medicine physician, because everyone, in their own way is an athlete as
some level.

Dr.
Narson practices in Miami Beach with his partner and wife, Dr. Corey
Narson. Drs. Narson has lived in Miami Beach since 1993 where they
also raise their children.

Dr. Narson is an active triathlete and member of the South Florida Triathletes Hammerheads triathlon club. He is holds a 1st dan blackbelt in shotokan karate.